Ch. 24: Carbohydrates

Question 1

Pyranose ring (hemiacetal formation)

Answer 1

Reagent: [H+]
Product: Ring with -OH and -H (from Aldehyde)

Question 2

Furanose ring (hemiacetal formation)

Answer 2

Reagent: [H+]
Product: Ring with -OH and CH2OH (from Ketone)

Question 3

Acetylation (reagent & product)

Answer 3

Reagent: Ac2O, Py
Product: -Ac replaces -H

Question 4

Alkylation (reagent & product)

Answer 4

Reagent: Ch3I, Ag2O
Product: -CH3 replaces -H

Question 5

Glycoside formation (reagent & product)

Answer 5

Reagent: CH3OH, HCl
Product: -OCH3 replaces -OH that formed ring

Question 6

Reduction (reagent & product)

Answer 6

Reagent: NaBH4, H2O
Product: Reduces one end to CH2OH

Question 7

Partial oxidation (aldonic)

Answer 7

Reagent: Br2, H2O
Product: oxidizes top end to COOH (carboxylic acid)

Question 8

Full oxidation (aldaric)

Answer 8

Reagent: HNO3, H2O, heat
Product: oxidizes both ends to COOH (carboxylic acid)

Question 9

Chain Lengthening (Kiliani-Fischer)

Answer 9

1. HCN 2. H2, Pd/BaSO4, H2O

Question 10

Chain Shortening (Wohl)

Answer 10

1. NH2OH 2. Ac2O 3. NaOMe